Abstract

LiNi0.5Mn1.5−xSnxO4 (0 ≤ x ≤ 0.1) cathode materials with uniform and fine particle sizes were successfully synthesized by a two-step calcination of solid-state reaction method. As the cathode materials for lithium ion batteries, the LiNi0.5Mn1.48Sn0.02O4 shows the highest specific capacity and cycle stability. In the potential range of 3.5–4.9 V at room temperature, LiNi0.5Mn1.48Sn0.02O4 composite material shows a discharge capacity of more than 117 mA h g−1 at 0.1 C, while the corresponding discharge capacity of undoped LiNi0.5Mn1.5O4 is only 101 mA h g−1. Moreover, in cycle performance, all the LiNi0.5Mn1.5−xSnxO4 (0 ≤ x ≤ 0.1) samples show better capacity retention than the undoped LiNi0.5Mn1.5O4 at 1 C rate after 100 cycles. Especially, for the LiNi0.5Mn1.5O4, the discharge capacity after 100 cycles is 90 mA h g−1, while the corresponding discharge capacities of the undoped LiNi0.5Mn1.5O4 is only 56.1 mA h g−1. The significantly enhanced DLi+ and the enlarged electronic conductivity make the Sn-doped spinel LiNi0.5Mn1.5O4 material present even more excellent electrochemical performances. These results reveal that Sn-doping is an effective way to improve electrochemical performances of LiNi0.5Mn1.5O4.

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Abstract

Acknowledgment

This work was supported by the Science and Technology Program of WeiHai (2015DXGJMS017), and HIT & Yun Shan Group Research and Development on Graphite Area.

Interest statement

The authors declare that they have no conflict of interest.

Contributions statement

Liu H convinced the idea of the research; Hao J performed the experiments and wrote the manuscript. All authors contributed to the general discussion.

Author information

Jingmin Hao is currently a graduate student majored in electrochemistry at the School of Marine Science and Technology, Harbin Institute of Technology, Weihai. Her research interest includes tuning the morphology of LiNi0.5Mn1.5O4 to optimize its electrochemical properties.

Haiping Liu received her BSc degree in chemical engineering from Qilu University of Technology in 1998, and her MSc and PhD degrees in chemical engineering and technology in 2004 and 2008, respectively, from Harbin Institute of Technology. Then, she joined Harbin Institute of Technology, Weihai as a faculty and became an associate professor of applied chemistry in 2013. Her research interests include electrodeposition, surface finishing, electrode materials, and graphene composite materials for Li-ion batteries.